Based on the results of the research, the orientation of the processes of forming the optimal nutrient regime on drained organic soils under corn for grain was determined by establishing scientifcally based doses of mineral fertilizers, depending on the methods that take into account the characteristics of these soils and methodological approaches to determine the doses of mineral fertilizers in the conditions of feld stationary experiment on drained organic soils of the floodplain of the Supii River. It was established that the application of mineral fertilizers leads to the strengthening of mineralization processes, which rises with increasing doses of fertilizers, which, in turn, leads to the accumulation of nutrients that affect the yield of cultivated crops and their migration into drainage waters. The increase in the content of nitrogen (N-NO3, N-НН4) and phosphorus (P2O5) compounds in drained organic soil are caused by both organic matter mineralization and mixing of vivianite and freshwater shells layers with peat soil, which causes an intensive oxidation process in the combined with CaСО 3 compounds, and as a result, organic matter decomposes into a partially humic complex of organic and mineral substances. Available for corn consumption nutrients further accumulate in the soil. The highest yield of corn per grain (8.34 t/ha) was obtained with the application of fertilizer doses based on the data of long-term studies (P45K120 with the addition of 2.0 l/ha of the combined preparation with the growth stimulator "Organic Balance"). The introduction of such doses of mineral fertilizers provides the greatest increase in yield per unit of applied fertilizers, and their leaching into drainage waters did not exceed the maximum permissible concentrations of water management objects for economic and cultural and domestic use. The use of justifed doses of fertilizers in corn crops ensures the highest yield with cost-effective costs per unit of production. It also takes into account the environmental aspects of mineral fertilizers, which prevent excessive leaching of biogenic substances into drainage waters, and, as a result, reduces the pollution of river waters.

Key words: macrofertilizers, growth stimulator, calculation methods, fertilizers, organic soils, corn, ecology, productivity.